DESCRIPTION: (Applicant's Abstract) Since the early 1980s I have devoted my efforts to developing and applying novel techniques for in vivo imaging of neurotransmitters and receptor systems in-patients with normal physiology and those with neuropsychiatric disorders. These methods are the tools used to ask neurochemical questions in human imaging research. My most recent research is focused on drug abuse, better methods to treat it and the comorbidity of substance abuse and neuropsychiatric diseases. The ultimate goal of this research is to understand the pathophysiological mechanisms associated with drug abuse and to apply them to the development of new and promising therapies for addiction. This award will provide me with the additional time needed to consolidate and strengthen my laboratory's patient oriented research in drug abuse. It will help improve my research productivity and provide the time to focus on improvements in techniques and scientific networking. It will provide an important infrastructure, not only for my own personal efforts but also for my junior colleagues. Their efforts will be greatly enhanced, as well through the mentoring plan that I will be able to establish and perpetuate with the assistance of this long term funding. In this resubmission we have attempted to address all of the concerns of the reviewers. In particular, we have specifically indicated there would be a 50% decrease in clinical, administrative and clinical teaching to allow additional time for research and mentorship. Furthermore, institutional support for a specific departmental role in mentorship as well as other institutional letters at the level of the Dean's office have been incorporated. Finally more details concerning the specifics of our research plan, additional training opportunities for myself and explicit increased numbers of mentorship opportunities are outlined in detail and tabulated. In summary, I feel that this midcareer award would come at an extremely important point in my career and would make a significant difference by allowing me to more fully direct my attention to the timely issues of the pathophysiology of substance abuse and new approaches to its treatment.